Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"bioactivity evaluation"”.
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Host-defence peptides from frog skin secretions: identification and bioactivity evaluation and optimisation
… proline and glycine could both influence the bioactivity of peptide while the proline exhibited stronger impact than the glycine residue and where the kink structure interrupted helical structure, was critical to balance the antimicrobial activity and haemolytic activity. To test the …
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Identification and bioactivity evaluation of a novel peptide from the skin secretion of Pelophylax kl. esculentus
Species of frogs and toads have proven to be a rich source of drugs and contain various components with potential biological activities, especially in their skin or skin secretions. Among these, peptides are found with broad-spectrum antibacterial and antifungal activities, as well as anticancer …
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Characterisation, bioactivity evaluation and rational modification of bioactive peptides from frog skin secretion and scorpion venom
This thesis examines a range of bioactive peptides from the East Asia frog- Pelophylax nigromaculatus, the Chinese bamboo leaf frog - Odorrana versabilis, and the scorpion Androctonus bicolor. In chapter 3 a novel Bowman-Birk type protease inhibitor (ranacyclin-NF) was identified in the skin …
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Bioactivity evaluation and structural modification of Bowman-Birk type protease inhibitory peptides from amphibian skin secretions
… The truncated analogue, QUB-1879 showed better bioactivity on protease inhibition and anti-proliferation. In addition, negligible LDH releasing was observed when treated by QUB-1879. In Chapter 5, the trypsin inhibitory loop was linked to Tat49-57 to improve the biological activities and …
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Identification and bioactivity evaluation of an amphibian skin Bowman-Birk-like trypsin inhibitor from Hylarana nigrovittata
As a result of fighting fungal and microbial infections in their living environment, granular glands of amphibian skin can produce various compounds, especially peptides and proteins, which are useful for preventing bacterial and fungal infections. Among these bioactive compounds, serine protease …
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Discovery, bioactivity evaluation and rational design of natural-occurring peptides from Agalychnis annae and Rana tagoi okiensis
There are multiple biofunctional peptides in amphibians which assist in their survival in diverse environments. Many bioactive peptides from this source were found to have the potential to be developed into new drugs in the future. In this thesis, two peptides found in frogs and their analogues …
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Bioactivity evaluation of peptide QUB-1480 from the skin secretion of the Green Cascade frog (Odorrana livida)
… peptide family of AMPs for their multiple bioactivity aiming at microorganism killing, cancer diminishing or protease inhibiting. The research, therefore, will be focused mainly on the peptides isolated from the skin secretion of the amphibian Odorrana livida.<br/><br/>In this thesis, a …
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Bioactivity evaluation of peptide QUB-1817 from the skin secretion of the Chinese brown frog (Rana chensinensis)
Bioactive peptides from amphibian skin secretions have attracted much attention from researchers because of their profound significance in novel drug development. Many amphibian skin-derived peptides have been proven to possess antimicrobial activity, anticancer activity as well as …
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The discovery and bioactivity evaluation of a novel peptide, QUB-2652, from the skin secretion of the South American frog, Phyllomedusa palliata
In recent years, the antibiotic resistance of bacteria has stimulated the development of new antibiotics. Antimicrobial peptides (AMPs) from amphibian skin secretions possess broad-spectrum antimicrobial activities through the mechanism that is unlikely to induce antibiotic resistance. Thus, AMPs …
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The discovery and bioactivity evaluation of a novel peptide, QUB-1925, and its modified analogue, QUB-2067, from the defensive skin secretion of the frog, Phyllomedusa coelestis
… synthetic replicate of QUB-1925 was subjected to bioactivity and toxicity tests. Finally, QUB-1925 was found to have no potent antimicrobial activity against tested microorganisms but to have haemolytic activity at high concentrations. Thus, QUB-1925 was structurally modified to create an analogue …
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Searching for Anticancer Agents and Antimalarial Agents from Madagascar
… elucidation, this dissertation also involve bioactivity evaluation of all the isolates, synthesis of two interesting alkaloids, as well as a proposal for the possible biosynthetic pathway of the new cyclohepta-dibenzofuran skeleton.
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Identification and functional study of the antimicrobial peptide, QUB- 1985, from the skin secretion of the large odorous frog, Odorrana livida
… Odorous Frog, Odorrana livida. The results of bioactivity evaluation on this peptide demonstrated that QUB-1985 could exhibit antimicrobial activity on a Gram-negative bacterium (Escherichia coli, MIC=16 μM) and a Gram-positive bacterium (Staphylococcus aureus, MIC=64 μM) in a dose-related …
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Synthesis and evaluation of quinoline-5,8-diones and isoquinoline-5,8-diones as anticancer agents
… and isoquinoline-5,8-diones families with bioactivity evaluation. Chapters 4, 5, 6, 7 and 8 are focused on the development and biological screening of the quinoline-5,8-dione library; Chapters 9 and 10 construct and evaluate the isoquinoline-5,8-dione library. Initial route development …
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Discovery and functional study of the novel bioactive peptide QUB-1980 from the skin secretion of Odorrana grahami
… spectrum against tested strains. The bioactivity of QUB-1348V was compared with the parent peptide to study the significance of “Rana box” in the novel peptide QUB-1980. Besides, it also exhibited a mild toxicity to horse red blood cell. Besides, by substituting the “Rana box” with a …
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Identification and activity assessment of a bioactive peptide QUB-1368 from the skin secretion of the American bullfrog (Rana catesbeiana)
Polypeptides in amphibian skin secretions have various bioactive functions, especially the positively-charged, alpha-helical and amphipathic polypeptides. In this study, a novel antimicrobial peptide isolated from the skin secretions of Rana catesbeiana was named QUB-1368. After establishing the …
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Chemical aspects of saponin bioactivity and ovine photosensitization diseases
… from East Cape Manuka oil were subjected to a bioactivity evaluation against a range of bacterial and fungal organisms using the agar gel well diffusion technique. A possible structure-activity relationship amongst the synthesized saponins is discussed. The activity of triketone oil against two …
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Identification and functional study of the bioactive peptide QUB-2417 from the skin secretion of the tree frog, Phyllomedusa bicolor
… In the MTT assay, QUB-2417 exhibited bioactivity against lung cancer cell line NCI-H838 at the highest test concentration (10-4 M) and the value of IC50 was 35.3 µM. In the haemolysis bioassay, QUB-2417 exhibited about 30% haemolytic effect at the highest test concentration (128 μM) …